1. Technical Field
The present disclosure relates to an imaging apparatus such as a camera.
2. Description of the Related Art
In recent years, distance measuring apparatuses which measure a distance from a subject (target of distance measurement) based on a parallax between a plurality of imaging optical systems are used for the measurement of vehicular gaps between automobiles and in camera auto-focus systems and three-dimensional shape measurement systems.
In such distance measuring apparatuses, a pair of imaging optical systems that are positioned in right-left or upper-lower relationship create images in their respective imaging regions, such that a distance from the subject is detected from the parallax between these images based on triangulation.
As a method of measuring a distance from a subject with a single imaging optical system, a DFD (Depth From Defocus) technique is known. Although the DFD technique is a technique for calculating a distance by analyzing an amount of blur of an acquired image, it is impossible to know from a single image whether something is a pattern possessed by the subject itself, or a blur caused by subject distance; therefore, a technique of estimating a distance from a plurality of images is adopted (Patent Document 1 (Japanese Patent No. 3110095), Non-Patent Document 1 (Xue Tu, Youn-sik Kang and Murali Subbarao Two- and Three-Dimensional Methods for Inspection and Metrology V. Edited by Huang, Peisen S. Proceedings of the SPIE, Volume 6762, pp. 676203 (2007))).